A recent residential project off the N11 near Stillorgan ran into trouble with fill settlement six months after handover. The contractor had placed granular fill without a compaction specification, assuming the local gravelly tills would densify under traffic. The problem was moisture. Dublin's glacial tills can hold water unexpectedly, and without a defined moisture-density relationship, achieving uniform compaction is guesswork. That is where the Proctor test becomes the starting point for any earthworks specification. By establishing the relationship between moisture content and dry density for a specific borrow source, the test gives site teams a clear target. In our experience across Dublin, from Tallaght to Balbriggan, a properly executed sand cone density field check paired with a laboratory Proctor curve prevents exactly this type of post-construction settlement.
A Proctor curve is not just a lab number; it is the compaction fingerprint of a specific borrow source, and in Dublin's patchy glacial geology, that fingerprint changes fast.
